(a) Field of the Invention
The present invention relates to a plasma display panel, and more particularly, to a surface discharge-type plasma display panel having an electrode structure in which a pair of discharge sustain electrodes that generate display discharge is mounted corresponding to each discharge cell between two substrates.
(b) Description of the Related Art
A plasma display panel (PDP) is typically a display device in which ultraviolet rays generated by the discharge of gas excite phosphors to realize predetermined images. As a result of the high resolution possible with PDPs (even with large screen sizes), many believe that they will become a major, next generation flat panel display configuration.
In a conventional PDP, with reference to FIG. 5, address electrodes 51 are formed along one direction (direction X in the drawing) on second substrate 50. Dielectric layer 53 is formed over an entire surface of second substrate 50 on which address electrodes 51 are formed such that dielectric layer 53 covers address electrodes 51. Barrier ribs 55 are formed on dielectric layer 53 in a line pattern and at locations between address electrodes 51. Red, green, and blue phosphor layers 57 are formed between barrier ribs 55 are.
First substrate 60 is provided opposing second substrate 50. Discharge sustain electrodes 64 are formed on a surface of first substrate 60 facing second substrate 50. Each of discharge sustain electrodes 64 includes a pair of transparent electrodes 62 and a pair of bus electrodes 63. Transparent electrodes 62 and bus electrodes 63 are arranged in a direction substantially perpendicular to address electrodes 51 of first substrate 60 (i.e., along direction Y). Dielectric layer 66 is formed over an entire surface of first substrate 60 on which discharge sustain electrodes 64 are formed such that dielectric layer 66 covers discharge sustain electrodes 64. MgO protection layer 68 is formed covering dielectric layer 66.
Areas between where address electrodes 51 of second substrate 50 and discharge sustain electrodes 64 of first substrate 60 intersect become areas that form discharge cells.
An address voltage Va is applied between address electrodes 51 and discharge sustain electrodes 64 to perform address discharge. Then a sustain voltage Vs is applied between a pair of discharge sustain electrodes 64 to perform sustain discharge. Ultraviolet rays generated at this time excite corresponding phosphor layers 57 such that visible light is emitted through first substrate 60, which is transparent, to realize the display of images.
Discharge sustain electrodes 64 will be described in greater detail with reference now to FIG. 6. Transparent electrodes 62 are formed substantially perpendicular to the direction of barrier ribs 55 as described above. Transparent electrodes 62 comprising each pair that form discharge sustain electrodes 64 are provided at a predetermined distance from each other. That is, each pair of transparent electrodes 62 occupies a predetermined space along direction X. Also, a predetermined spacing is used between adjacent pairs of transparent electrodes 62. Bus electrodes 63 enhance electric conductivity and are formed such that one of bus electrodes 63 is provided along a long edge of each of transparent electrodes 62 to thereby complete the formation of discharge sustain electrodes 64.
In an alternative conventional configuration, with reference to FIG. 7, discharge sustain electrodes 74 are formed including a pair of bus electrodes 73 provided substantially perpendicular to barrier ribs 55 (along direction Y), and transparent electrodes 72 formed extending from bus electrodes 73 to be positioned within each discharge cell. Transparent electrodes 72 are formed in a T-shape with the base of the “T” connected to bus electrodes 73 as shown in the figure.
However, with respect to the structure shown in FIGS. 5 and 6 in which each pair of transparent electrodes 62 occupies a predetermined space along direction X, since a uniform field is not formed over the entire surface of transparent electrodes 62 when a voltage is applied to discharge sustain electrodes 64 to effect discharge, many unnecessary areas of transparent electrodes 62 result which contribute little to discharge. In addition to reducing discharge efficiency within the discharge cells, these areas reduce brightness by screening a significant region of the discharge cells.
Further, when forming transparent electrodes 72 in a T-shape as shown in FIG. 7, a situation results where discharge is concentrated at corner areas of transparent electrodes 72. This prevents the uniform spreading of discharge within the discharge cells.